[test] Fix expectations in WebKit JSON.stringify tests

The reference implementation used in the tests does not fully match
the spec, so for the diverging cases we need to explicitly specify
the correct expectation.

Every single change in this patch has been verified against every
major JavaScript engine using eshost + jsvu. All implementations
match the spec (and the V8 implementation), with the following two
exceptions:

- One expectation was wrong because of a JavaScriptCore bug (that
  is, we inherited the incorrect expectation when importing the
  tests from WebKit). A comment was added for that one.
- This work resulted in the discovery of bugs in Moddable/XS:
  https://github.com/Moddable-OpenSource/moddable/issues/112

Change-Id: I05d91d7acc5c8765e941fcd68c1086c2694c710c
Reviewed-on: https://chromium-review.googlesource.com/c/1396081Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58546}

test/webkit/resources/JSON-stringify.js

@@ -88,10 +88,10 @@ function createTests() {
     result[result.length - 1].expected = '2';
     result.push(function (jsonObject){
         var value = new Boolean(true);
-        value.valueOf = function() { return 2; };
+        value.valueOf = function() { return false; };
         return jsonObject.stringify(value);
     });
-    result[result.length - 1].expected = '2';
+    result[result.length - 1].expected = 'true';
     result.push(function (jsonObject){
         var value = new String("fail");
         value.toString = function() { return "converted string"; };
@@ -114,10 +114,13 @@ function createTests() {
     result.push(function (jsonObject){
         return jsonObject.stringify({toJSON: Date.prototype.toJSON, toISOString: function(){ return "custom toISOString"; }});
     });
+    // Note: JSC fails the following test. Every other engine matches the spec.
+    // This is also covered by the test in
+    // https://github.com/v8/v8/blob/fc664bda1725de0412f6d197fda9503d6e6e122e/test/mjsunit/json.js#L78-L80
     result.push(function (jsonObject){
         return jsonObject.stringify({toJSON: Date.prototype.toJSON, toISOString: function(){ return {}; }});
     });
-    result[result.length - 1].throws = true;
+    result[result.length - 1].expected = '{}';
     result.push(function (jsonObject){
         return jsonObject.stringify({toJSON: Date.prototype.toJSON, toISOString: function(){ throw "An exception"; }});
     });
@@ -162,6 +165,7 @@ function createTests() {
         jsonObject.stringify([1,2,3,4,5], function(k,v){allString = allString && (typeof k == "string"); return v});
         return allString;
     });
+    result[result.length - 1].expected = true;
     result.push(function (jsonObject){
         var allString = true;
         var array = [];
@@ -332,9 +336,11 @@ function createTests() {
     result.push(function (jsonObject){
         return jsonObject.stringify(objectWithSideEffectGetter);
     });
+    result[result.length - 1].expected = '{}';
     result.push(function (jsonObject){
         return jsonObject.stringify(objectWithSideEffectGetterAndProto);
     });
+    result[result.length - 1].expected = '{}';
     result.push(function (jsonObject){
         return jsonObject.stringify(arrayWithSideEffectGetter);
     });
@@ -351,7 +357,7 @@ function createTests() {
         jsonObject.stringify([1,2,3,,,,4,5,6], replaceFunc);
         return replaceTracker;
     });
-    result[result.length - 1].expected = '(string)[1,2,3,null,null,null,4,5,6];0(number)1;1(number)2;2(number)3;3(number)undefined;4(number)undefined;5(number)undefined;6(number)4;7(number)5;8(number)6;'
+    result[result.length - 1].expected = '(string)[1,2,3,null,null,null,4,5,6];0(string)1;1(string)2;2(string)3;3(string)undefined;4(string)undefined;5(string)undefined;6(string)4;7(string)5;8(string)6;';
     result.push(function (jsonObject){
         replaceTracker = "";
         jsonObject.stringify({a:"a", b:"b", c:"c", 3: "d", 2: "e", 1: "f"}, replaceFunc);
@@ -432,7 +438,7 @@ function createTests() {
         try { jsonObject.stringify(cyclicArray); } catch { cycleTracker += " -> exception" }
         return cycleTracker;
     });
-    result[result.length - 1].expected = "0(number):[object Object]first, -> exception";
+    result[result.length - 1].expected = "0(string):[object Object]first, -> exception";
     function createArray(len, o) { var r = []; for (var i = 0; i < len; i++) r[i] = o; return r; }
     var getterCalls;
     var magicObject = createArray(10, {abcdefg: [1,2,5,"ab", null, undefined, true, false,,],

test/webkit/run-json-stringify-expected.txt

@@ -58,10 +58,10 @@ function (jsonObject){
 PASS tests[i](nativeJSON) is tests[i].expected
 function (jsonObject){
         var value = new Boolean(true);
-        value.valueOf = function() { return 2; };
+        value.valueOf = function() { return false; };
         return jsonObject.stringify(value);
     }
-FAIL tests[i](nativeJSON) should be 2. Was true.
+PASS tests[i](nativeJSON) is tests[i].expected
 function (jsonObject){
         var value = new String("fail");
         value.toString = function() { return "converted string"; };
@@ -91,7 +91,7 @@ PASS tests[i](nativeJSON) is tests[i](JSON)
 function (jsonObject){
         return jsonObject.stringify({toJSON: Date.prototype.toJSON, toISOString: function(){ return {}; }});
     }
-FAIL tests[i](nativeJSON) should throw an exception. Was {}.
+PASS tests[i](nativeJSON) is tests[i].expected
 function (jsonObject){
         return jsonObject.stringify({toJSON: Date.prototype.toJSON, toISOString: function(){ throw "An exception"; }});
     }
@@ -143,7 +143,7 @@ function (jsonObject){
         jsonObject.stringify([1,2,3,4,5], function(k,v){allString = allString && (typeof k == "string"); return v});
         return allString;
     }
-FAIL tests[i](nativeJSON) should be false. Was true.
+PASS tests[i](nativeJSON) is tests[i].expected
 function (jsonObject){
         var allString = true;
         var array = [];
@@ -355,11 +355,11 @@ PASS tests[i](nativeJSON) is tests[i](JSON)
 function (jsonObject){
         return jsonObject.stringify(objectWithSideEffectGetter);
     }
-FAIL tests[i](nativeJSON) should be {"foo":1}. Was {}.
+PASS tests[i](nativeJSON) is tests[i].expected
 function (jsonObject){
         return jsonObject.stringify(objectWithSideEffectGetterAndProto);
     }
-FAIL tests[i](nativeJSON) should be {"foo":1}. Was {}.
+PASS tests[i](nativeJSON) is tests[i].expected
 function (jsonObject){
         return jsonObject.stringify(arrayWithSideEffectGetter);
     }
@@ -373,7 +373,7 @@ function (jsonObject){
         jsonObject.stringify([1,2,3,,,,4,5,6], replaceFunc);
         return replaceTracker;
     }
-FAIL tests[i](nativeJSON) should be (string)[1,2,3,null,null,null,4,5,6];0(number)1;1(number)2;2(number)3;3(number)undefined;4(number)undefined;5(number)undefined;6(number)4;7(number)5;8(number)6;. Was (string)[1,2,3,null,null,null,4,5,6];0(string)1;1(string)2;2(string)3;3(string)undefined;4(string)undefined;5(string)undefined;6(string)4;7(string)5;8(string)6;.
+PASS tests[i](nativeJSON) is tests[i].expected
 function (jsonObject){
         replaceTracker = "";
         jsonObject.stringify({a:"a", b:"b", c:"c", 3: "d", 2: "e", 1: "f"}, replaceFunc);
@@ -451,7 +451,7 @@ function (jsonObject){
         try { jsonObject.stringify(cyclicArray); } catch { cycleTracker += " -> exception" }
         return cycleTracker;
     }
-FAIL tests[i](nativeJSON) should be 0(number):[object Object]first, -> exception. Was 0(string):[object Object]first, -> exception.
+PASS tests[i](nativeJSON) is tests[i].expected
 function (jsonObject){
         getterCalls = 0;
         return jsonObject.stringify(magicObject) + " :: getter calls = " + getterCalls;